The president of the World Jewish Congress was one of the biggest backers of a secretive group that spent millions of dollars on targeted campaign ads predicting a Muslim takeover of the United States.

Ronald Lauder gave $1.1 million to the group Secure America Now, the watchdog group Open Secrets revealed Thursday, citing IRS forms it had acquired. Secure America Now is not required to disclose its donors.

The organization’s biggest individual backer, at $2 million, was Robert Mercer, the hedge fund investor whose family has bankrolled Breitbart News and the data company Cambridge Analytica, which has been accused of improperly using Facebook data to sway prospective voters.

Secure America Now’s ads featured mock promotional travel ads portraying countries that had been taken over by the Islamic State. In one ad, the Statue of Liberty wears a burka and the Hollywood sign is changed to “Allahu Akbar.”

Secure America Now reported more than $1 million in political spending to the Federal Election Commission in 2016. The group reportedly used targeted advertising on Facebook and Google to reach potential voters in swing states and districts.

“STOP SUPPORT OF TERRORISM. VOTE AGAINST CATHERINE CORTEZ MASTO,” one ad said at its conclusion, referring to a Democratic senate candidate in Nevada.

Elliott Broidy, the Republican Jewish megadonor whose efforts to influence President Trump’s Middle East policies, referred to Secure America Now as “one of the groups I am working with” in an email to an advisor to the United Arab Emirates whose activities are under investigation by special counsel Robert Mueller.